Ice-core Volcanic Index 2 (IVI2)

Ice-Core-Based Volcanic Atmospheric Injection and Loading for the Past 1500 Years
 
Chaochao Gao, Alan Robock, and Caspar Ammann
Department of Environmental Sciences
Rutgers University
Email: chaogao08@gmail.com, robock@envsci.rutgers.edu, and ammann@ucar.edu

THE DATA SET HAS BEEN REVISED.  SEE VERSION 2 BELOW.

The data set is described in the paper:

Gao, Chaochao, Alan Robock, and Caspar Ammann, 2008:  Volcanic forcing of climate over the past 1500 years: An improved ice-core-based index for climate models.  J. Geophys. Res., 113, D23111, doi:10.1029/2008JD010239.  PDF file  Correction1  Correction2  NOTE:  The version of the paper here includes the corrections, which do nothing to change the data set or the conclusions.

ABSTRACT:

Understanding natural causes of climate change is vital to evaluate the relative impacts of human pollution and land surface modification on climate.  We have investigated one of the most important natural causes of climate change, volcanic eruptions, by using 54 ice core records from both the Arctic and Antarctica.  Our recently collected suite of ice core data, more than double the number of cores ever used before, reduces errors inherent in reconstructions based on a single or small number of cores, which enables us to obtain much higher accuracy in both detection of events and quantification of the radiative effects.  We extracted volcanic deposition signals from each ice core record by applying a high-pass LOESS filter to the time series and examining peaks that exceed twice the 31-year running median absolute deviation.  We then studied the spatial pattern of volcanic sulfate deposition on Greenland and Antarctica, and combined this knowledge with a new understanding of stratospheric transport of volcanic aerosols to produce a forcing data set as a function of month, latitude, and altitude for the past 1500 years.  We estimated the uncertainties associated with the choice of volcanic signal extraction criteria, ice-core sulfate deposition to stratospheric loading calibration factor, and the season for the eruptions without a recorded month.  We forced an energy balance climate model with this new volcanic forcing data set, together with solar and anthropogenic forcing, to simulate the large scale temperature response.  The results agree well with instrumental observations for the past 150 years and with proxy records for the entire period.  Through better characterization of the natural causes of climate change, this new data set will lead to improved prediction of anthropogenic impacts on climate.  The new data set of stratospheric sulfate injections from volcanic eruptions for the past 1500 years, as a function of latitude, altitude, and month, is available for download in a format suitable for forcing general circulation models of the climate system.

REVISED DATA (VERSION 2):

READ ME (pdf): Data set descriptions
Data Set 1: (text) Hemispheric and Global Total Stratospheric Sulfate Aerosol Injection from Volcanic Eruptions, 501-2000 A.D.
Data Set 2: (text-150 Mb), (binary-54 Mb) Monthly and Spatially Dependent Stratospheric Loading from Volcanic Eruptions, 501-2000 A.D.

ORIGINAL DATA:

READ ME (pdf): Data set descriptions
Data Set 1: (text) Hemispheric and Global Total Stratospheric Sulfate Aerosol Injection from Volcanic Eruptions, 501-2000 A.D.
Data Set 2: (text-150 Mb), (binary-54 Mb) Monthly and Spatially Dependent Stratospheric Loading from Volcanic Eruptions, 501-2000 A.D.